Well the company that I am employed by uses spurs for most of it's power feeds. Some are many miles long (but at a higher voltage than 240V). Not only that but most of these supplies are "earth free" as in the supply wiring has no intentional connection to earth. The metal equipment covers and parts are however earthed for equipment over 110Vac.We use a very varied mix of equipment, including motors, relays and electronics including microprocessor and computer equipment.Some of this equipment has been in operation since 1970. We do have failures (locating and fixing these is my job) but most are caused by poor connections or cables (or contractors) that have degraded (or been hit by other department staff / machinery).

As far as electrical safety goes, this is the reason for the earth connections in electrical wiring - if a live conductor comes into contact with a metal case part, a fault current will flow and blow the fuse (or cause the MCB to trip out). "Modern" electronic equipment takes advantage of this, using the earth as a drain wire.

As to regards lightning strikes - if a metal cable going in your home suffers a direct strike anything connected to it will be toast! If your home gets hit anything that the current flows through will be damaged. And earthed items are the lightnings favorite path to earth!Even a nearby strike can cause much damage and a surge protector is only a limited defense. I do recommend using surge protectors, but just don't expect them to protect against such high energy sources!

Falcon, Atari 520STFM, Atari 1040STE, more PC's than I care to count and an assortment of 8 bit micros (nearly forgot the Psion's)

a ring main in any ac system supply residential differs from the system most retros expect as supply

the whole point of post like this is dont spur off a ring is to wake people up to the new laws that are europe widei have become aware of myselfso if you use an extenssion from a normal ring mainuse an anti surge filtered type extenssion for old pc and switchmode {analogue}its a pitty so many so called electricians dont offer to wire a seperate filtered computer only 4 way socketspre filered

instead they say your right or wrong instead of making a few quid offering this service...